The present invention relates to a tool holder for coupling of rotatable and/or striking tools with hand power tools, in particular with drill hammers or impact hammers.
In a known tool holder disclosed for example in the German patent document DE 32 05 063 C2 the tool shaft has two open driving grooves located at diametrically opposite points and having radial flanks which cooperate with associated surfaces of stripped shape drivers in the receiving opening of the coupling sleeve which receives the tool shaft. Two groove-shaped locking pockets which are closed at both sides in the axial direction are provided on the diagonals which are perpendicular to the diametrical points, on the outer surface of the tool shaft. They are used for axial holding of the tool in the tool holder. The locking bodies engage in the locking pockets and are formed as balls. The balls abut against a flat sheet metal ring which is supported on the displacement sleeve, in the part of the displacement sleeve located in immovable position in which the blocking surface is provided. Therefore, the balls are secured against radial displacement from the blocking pockets. For unlocking the tool, the displacement sleeve is displaced against the spring force so that the balls reach a region of the displacement sleeve located outside of the blocking surface, in which the balls are released for a radial displacement. During removal of the tool shaft from the coupling sleeve, the balls are moved from the locking pockets and the tool shaft is released. During insertion of the tool the end of the tool shaft presses the balls against the sheet metal ring and displaces the same until the balls leave the blocking surface of the displacement sleeve and can deviate radially outwardly, so that the tool shaft can be displaced under the balls. When the locking pockets reach the balls, the balls dig into the locking pockets, and the springs which were tensioned during the insertion step by displacement of the sheet metal ring are displaced under the blocking surface. The tool is thereby axially fixed in the tool holder with a gap in the axial direction.
In another known tool holder disclosed for example in the German patent document DE 35 06 008 C2 the torque transmission from the tool holder to the tool shaft is not performed through special drive grooves in the tool holder, but instead is performed through locking pockets. For this purpose the locking body engages the longitudinally extending cylindrical rollers which engage form-lockingly in the locking pockets with closed end sides, and the tool shaft is fixed both in the axial direction as well as in the rotary direction in the coupling sleeve. For removing the cylindrical rollers from the locking pockets, the displacement path in the displacement sleeve must be greater than the length of the cylindrical rollers, which must be as long as possible for transmission of a great torque. In order to shorten the displacement path, each locking body which is formed of two parts has a sliding block with an abutment projection near the cylinder roller. The blocking surface of the sliding sleeve is stepped and provided with two radially offset control surfaces, which cooperate also with two radially stepped surface portions of the periphery of the sliding block. The sliding block is located on the associated cylindrical roller and over engages with its radial abutment projections the end side of the cylinder roller which is located behind in the insertion direction of the tool shaft. A pressure spring which acts against the insertion direction of the tool shaft loads the sliding block in an axial direction and presses it against an abutment on the displacement sleeve.